Filter presses are well known and extensively utilized for separately solids from slurries. Such presses employ a plurality of filter plates which are held in contacting relationship between fixed and movable head members while the slurry is pumped into and through the press for collecting the solid in the form of filtrate or cake between adjacent filter plates. When the press is full, then the movable head is backed away from the plates into an open position and, in one conventional type of press, the plates are then individually and sequentially moved into an open position adjacent the movable head to permit discharge of the cake which has collected between adjacent pairs of plates. To permit movement of the plates into an open position, plate shifting mechanisms are typically provided adjacent opposite sides of the press for permitting either automatic or manual control over the plate movement and cake discharge.
In a conventional press, a pair of substantially identical plate shifter mechanisms are typically provided adjacent opposite sides of the press for synchronous cooperation with handles of the individual plates, whereby the shifter mechanisms reciprocate back and forth along the press side rails so as to individually but sequentially move each plate toward the movable opened head for permitting filtrate discharge. These mechanisms typically each employ a pair of movable stops or pawls, one for abutting the leading plate in the stack to prevent advancing movement of the shifter mechanisms, the other for engaging the opposite side of the leading plate to move it toward the movable head when the shifter mechanism is moved in the opposite direction. One example of such mechanism is disclosed in Assignee's earlier U.S. Pat. No. 4,963,255.
The conventional filter presses have often operated in a less than satisfactory manner, particularly when utilized with materials which result in a filtrate or cake having "sticky" properties. That is, relying solely on gravity to cause discharge of "sticky" cake from between the opened filter plates is often insufficient to effect proper discharge since the cake tends to stick to the filter cloths or membranes of the plates. It is often conventional practice to manually assist the discharge by having an operator scrape the sticky cake from the filter plates by use of a paddle or the like.
In an attempt to effect automatic discharge of sticky cake, and avoid the requirement of manual assistance, an attempt has been made to utilize air nozzles for blasting air against the cake to assist in loosening of the filtrate from the plate. Such arrangement is disclosed in Assignee's prior U.S. Pat. No. 5,328,617. The Assignee has also attempted to assist discharge by utilizing a vibrating or bumping device, but such device, as also disclosed in aforementioned U.S. Pat. No. 5,328,617, is a wholly independent mechanism provided on the arch of an arch-type shifting mechanism, and the bumping mechanism of this '617 patent engages the lead plate in the stack and effects bumping thereof only when the plate is still engaged with the stack, following which the plate is then moved into the open position. While this bumping is believed effective in assisting dislodgement of cake, nevertheless the position of the bumping and the mounting of the mechanism as disclosed in the '617 patent is not believed to provide for optimum utilization of this bumping characteristic.
In another known press, specifically a press manufactured and sold by Perrin of Canada, the filter plates are joined together through a control device such as a cable or linkage so that, during opening of the press, all of the plates are substantially simultaneously moved into an open separated condition with the spacing or separation between each adjacent pair of plates being controlled by the connecting linkage. All of the plates, adjacent one side thereof, are supported on an elongate tube which extends longitudinally along the press and is of square or rectangular profile. This tube is then rotated to impose a vibration or bouncing movement on the handles provided adjacent one side of the filter plates, whereby all of the plates are simultaneously vibrated to assist in discharge of the sticky cake. While this arrangement is at least partially effective for permitting discharge of sticky cake, nevertheless such arrangement is undesirable from a structure standpoint since it requires an additional vibrating drive shaft extending longitudinally throughout substantially the length of the press, and in addition requires a long support frame or support rail arrangement since all of the filter plates are moved into an opened and spaced relationship at the same time.
Accordingly, it is an object of this invention to provide an improved shifter mechanism for a filter press, which mechanism incorporates a vibrating mechanism for effecting bumping of individual filter plates as they are moved in an opening direction so as to assist in dislodgement of filtrate therefrom.
It is also an object of the invention to provide an improved shifter mechanism, as aforesaid, which is of simple structure and operation, is inexpensive to construct, is reliable in operation, and provides a vibrating function for the filter plate at the same time as such plate is being moved in an opening direction without requiring extraneous complex structures or functions.
In the improved shifter mechanism of the present invention, as aforesaid, the mechanism includes a reciprocal housing which is supported for movement along the side rail and, in additional to the usual stop pawls for stopping shifter movement in one direction and effecting opening driving of the frontmost filter plate in the opposite direction, also includes a vibrator which is rotated in response to linear movement of the shifter mechanism carriage in said opposite direction, with this rotary vibrator in turn effecting raising of the filter plate being shifted, followed by dropping thereof onto the side rail so as to impose an impact thereon to assist in loosening of the filtrate adhered thereto.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.